That indignity was belatedly righted last year when her species—a raccoon relative unique to the cloud forests of Colombia and Ecuador—was properly identified at last as Bassaricyon neblina: the first new carnivorous mammal species described in the Western Hemisphere in 35 years

This year's list includes a lineup of startling creatures notable for their scrappiness, weirdness, thrift, and sloth. For instance:

A new sea anemone—Edwardsiella andrillae, discovered accidentally by a geology team testing an undersea robot—grows upside down from burrows in the Antarctic Ross Ice Shelf, two dozen tentacles dangling into the water below. It's the first species of anemone known to grow in ice.

There's also a new species of ghostly, raptorial skeleton shrimp, an eighth- to a tenth-of-an-inch long (two to three millimeters), collected from a cave on Santa Catalina Island off California. Called Liropus minusculus, they seem to live to pick fights with each other, yet are also caring mothers.

And then there's a fierce-looking, well-camouflaged gecko(Saltuarius eximius) that sports an odd, broad, flattened tail that resembles a leaf or lichen. Living in an isolated rain forest on Australia's Cape Melville, the approximately 4.5-inch-long (11.5 centimeters) lizard was discovered by an expedition funded by the National Geographic Expeditions Council.

View Images

A new species of leaf-tailed gecko sits on a tree trunk in Cape Melville National Park, Queensland, Australia.

Photograph by Tim Laman, National Geographic Creative

A Drop in the Bucket

Quentin Wheeler, president of SUNY-ESF and founding director of the International Institute for Species Exploration, says these animals represent a tiny sliver of the world's undiscovered species. There are perhaps 12 million species of plants, animals, and fungi—and about 50 million if you add bacteria and microbes called archaea—of which we've discovered and described fewer than two million.

"We have not increased our rate of species discovery and description at all since before World War II," said Wheeler. "It's pretty much a steady state of 17,000 to 18,000 species a year. Given the technological advances in recent decades, I find that really inexcusable. We could easily be working an order of magnitude faster."

Even worse, he says, human encroachment on natural habitats, deforestation, pollution, and climate change are causing species to go extinct before we can describe them.

According to a recent paper in Science, Earth will reach mass extinction status—defined as the loss of 75 percent or more of plant and animal species—within 300 years if current rates continue. The last time that happened? Sixty-five million years ago, when the asteroid that killed the dinosaurs struck the Earth.

"Some people say, 'Well, the Earth recovered from that one and is quite diverse and pleasant today,'" said Wheeler. "And that's true. The problem is it took tens of millions of years—and it wouldn't have been a very nice place to live during those tens of millions of years."

World of Wonders

Still, the biodiversity that remains is often mind-boggling.

Other species on this year's Top 10 list include a giant two-inch-long (five centimeters) single-celled organism (protist) called an agglutinated foraminifer (Spiculosiphon oceana), which welds its own skeleton together using organic glue and discarded silica sponge spicules—glassy sponge-skeleton components shaped like needles. When it's done, it looks remarkably like a carnivorous sponge. And it behaves like a carnivorous sponge too: It impales plankton on its pointy home and squeezes part of its body through gaps in its armor to feed on them.

There's also a new species of 250-micrometer-long parasitoid wasp called a fairy fly—the sweetly named Tinkerbella nana—whose delicate wings look like eyelashes glued to Q-tips; a hardy bacterium (Tersicoccus phoenicis) that survives in places food is virtually nonexistent and can withstand the heat of spacecraft clean-rooms, drying, UV light, and hydrogen peroxide treatments; a dragon tree, Dracaena kaweesakii; and a rusty-looking fungus (Pennicillium vanoranjei) named after the Prince of Orange of the Dutch royal family.

Rounding out the list is a land snail (Zospeum tholussum) that lives 3,000 feet (914 meters) down in a Croatian cave and may set a new land-creep record by moving only a few millimeters per week. When you live in pitch-dark over half a mile below the Earth's surface, speed doesn't seem to be of the essence.